Enzymatic hydrolysis of whey proteins by the combination of Alcalase and Neutrase: Kinetic model and hydrolysis control

A combination of Alcalase and Neutrase was used to hydrolyse whey proteins and the hydrolysis kinetics mechanism was studied to achieve accurate control of the hydrolysis process. By measuring the degree of hydrolysis (DH) at different enzyme concentrations and different substrate concentrations, the hydrolysis kinetic model was established as: DH=6.536Ln[1+(4.687E0S0–0.0007)t]. The results showed that the theoretical and actual values of the model were in good agreement. Subsequently, the molecular mass distribution of the whey proteins hydrolysates at different DH was determined; it was found that the molecular mass components of 5–20 and >20 kDa gradually decreased with the increase of DH, while the percentage of <1 kDa gradually increased. Extensive hydrolysis of whey proteins was achieved when the DH reached 21–25%. The establishment of kinetic model has theoretical guidance for the accurate control of the whey proteins hydrolysis by the combination of Alcalase and Neutrase.